Fiber optic components are used in a wide variety of applications. The use of optical fibers as a medium for transmission of digital data (including voice, internet and IP video data) is becoming increasingly more common due to the high reliability and large bandwidth available with optical transmission systems. Fundamental to these systems are optical subassemblies for transmitting and/or receiving optical signals.
Optical subassemblies typically comprise an interposer. As used herein, an interposer functions as a substrate for optical, opto-electrical, and electrical components and provides interconnections to optically and/or electrically interconnect the optical/opto-electrical/electrical components. There are many different configurations of interposers being used today. Of particular interest herein, are interposers comprising a glass substrate or carrier which is configured to receive and align various optical devices and to interengage a detachable optical interface having an array of lenses optically coupled to an optical conduit attached thereto such that the optical devices of the substrate are optically coupled with the optical conduit of the interface. Although this configuration continues to be effective in interfacing the optical conduit with the optical devices, the use of the glass substrate does present certain manufacturing challenges. In particular, glass can be difficult to etch accurately using known dry and wet etching techniques.
The manufacturability of the interposer may be improved by using materials having a crystalline structure, such as silicon. Such materials lend themselves to more accurate and faster etching. However, silicon is opaque for many of the wavelengths that are used commonly in optical applications. Therefore, there is a need for an interposer configuration that accommodates the opaqueness of silicon or other crystalline material. The present invention fulfils this need among others.